[U-Boot] [PATCH] arm: lpc32xx: Fix timer initialization

Gregory CLEMENT gregory.clement at bootlin.com
Wed Apr 17 09:48:45 UTC 2019

The match controller register is not cleared during
initialization. However, some bits of this register may reset the TC if
tnMRx match it.

As we can't make any assumption about how U-Boot is launched by the first
stage bootloader (such as S1L) clearing this register ensure that the
timers work as expected.

Signed-off-by: Gregory CLEMENT <gregory.clement at bootlin.com>
 arch/arm/cpu/arm926ejs/lpc32xx/timer.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/cpu/arm926ejs/lpc32xx/timer.c b/arch/arm/cpu/arm926ejs/lpc32xx/timer.c
index 404ccbb716..b3ca686040 100644
--- a/arch/arm/cpu/arm926ejs/lpc32xx/timer.c
+++ b/arch/arm/cpu/arm926ejs/lpc32xx/timer.c
@@ -33,6 +33,9 @@ static void lpc32xx_timer_reset(struct timer_regs *timer, u32 freq)
 	/* Set prescale counter value */
 	writel((get_periph_clk_rate() / freq) - 1, &timer->pr);
+	/* Ensure that the counter is not reset when matching TC */
+	writel(0,  &timer->mcr);
 static void lpc32xx_timer_count(struct timer_regs *timer, int enable)

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